Genetically Modified Mosquitoes to Fight Against Dengue
Overview Mosquitoes act as vectors for various disease-causing parasites and viruses. It is estimated that over 1 million people die per year due to being infected with mosquito-borne diseases, such as Malaria of Dengue Fever. A small UK-based company, called Oxitec, has created a cost effective and potential technique to help curb Dengue Fever within problem areas worldwide without any negative environmental impacts. This technique involves genetically modifying and releasing mosquitoes that are “sterile”. A factory in Brazil will soon be opened in order to raise and release these mosquitoes in hope to control Dengue Fever (2). Dengue Fever Case number of dengue fever has increased dramatically since the 1960s. This fever has become a global issue since World War II and is endemic in more than 110 countries. This is also known as breakbone fever, which is a mosquito-borne tropical disease caused by the dengue virus. It is transmitted through several species of mosquitoes, but primarily by Aedes aegypti and Aedea albopticus. The symptoms include: fever, headache, muscle and joint pains. Certain cases can develop into life-threatening dengue hemorrhagic fever which results in bleeding, low levels of platelets and blood plasma leakage. As of right now there is no commercially available vaccine. There are prevention techniques being implemented to decrease exposure to bites. Oral or intravenous rehydration has been used to mild or moderate cases. Severe cases have called for intravenous fluids and blood transfusions (4). Mosquito Control Techniques Mosquito nets are used primarily for controlling mosquitoes carrying malaria since they are mostly to bite at night time. Since mosquitoes carrying the dengue fever can bite at any time of the day mosquito nets aren't reliable. Insecticidal aerosols aren’t ideal due to the chemicals persisting in the environment and causing more problems, especially towards non-target species. There is also the issue of mosquitoes developing resistance towards chemicals, making them useless (2). One way to help control mosquitoes is the Sterile Insect Technique (SIT). This is a method of biological control which involves spraying mosquitoes with radiation to induce sterility then releasing them. The released insects are normally males, since the females cause the damage. The sterile males compete with the wild males for the female insects. If the female mates with the sterile male then there will be no offspring produced thus diminishing the next generation’s population (1). This technique has been proven to be difficult for mosquitoes versus using this technique on larger insects (2). Genetically Modified Mosquitoes Oxitec’s technique is considered the advancement on the method SIT. This involves inserting a lethal gene into male mosquitoes that prevents them from being able to successfully produce. They will release sterile males into the wild to compete with wild type male mosquitoes for females. The resultant progeny from the sterile males will contain the lethal gene that will prevent them from reaching sexual maturity. The insertion will also include a fluorescent tag called DsRedthat allows monitoruing of the mosquito populations after the release. Since the flight range of dengue mosquitos is within 200 yards and with this track and trace system, the population control can be highly maintained (2). References 1. Sterile Insect Technique. Wikipedia. http://en.wikipedia.org/wiki/Sterile_insect_technique 2. Alford, J. GM Mosquitoes Set to Be Released in Brazil to Combat Dengue. (July 23 2014). IFL Science. http://www.iflscience.com/health-and-medicine/gm-mosquitoes-set-be-released-brazil-combat-dengue-0 3. Mosquito. Wikipedia.http://en.wikipedia.org/wiki/Mosquito#Bites_and_treatment 4. Dengue Fever. Wikipedia. http://en.wikipedia.org/wiki/Dengue_fever